The Parker Class D8 (GCR Class 6DB) 4-4-0 Locomotives

The Manchester Sheffield & Lincolnshire Railway's (MS&LR, later GCR) Class 6DB locomotives were a development
of the MS&LR Class 6D 2-4-0 (LNER E2) design. The 6Ds were noted for
poor riding which was blamed on the single carrying axle. The new Class 6DB locomotives replaced the single carrying
axle with a leading two axle bogie. A total of three 6DBs were built at Gorton in 1888.

The D8s inherited a definite Sacre-look from the
E2. It also inherited the hybrid nature of the
E2 with double frames for the driving axles, but only a single
frame for the carrying axles. There is some evidence to suggest that this look was due
to Sacre continuing to remain at Gorton in an advisory capacity
for a few years. In contrast, the D8s also had some
Parker design elements such as the design of the chimney and
cab windows.

The D8s succeeded as stop-gaps, and solved the E2 problem of
poor riding. However, stop-gaps they were, and
Parker was a firm believer in single framed designs.
No more D8s were built.

Early in the 1900s, Robinson replaced the chimneys with his
own design, and fitted new smokeboxes. The original round-topped firebox boilers were placed by Belpaire firebox
boilers between 1910 and 1912. The new boilers were pitched slightly higher. At about the same time, the cab roofs
were extended to cover the entire footplate.

The D8s were initially put to work on the MS&LR's fastest trains to King's Cross. This work was shared with
the prototype D7, No. 561, but they were quickly replaced when the
D7s went into volume production. The D8s were moved to Liverpool in 1893 where they operated
the Liverpool to Hull services. Over time they were replaced by larger and more powerful locomotives. They moved to
Lincolnshire and were allocated to either Lincoln or New Holland. During 1920, No. 510a was regularly seen on
horse box specials from Newmarket to Haydock Park.

By 1922, all three were moved to Southport to work services to Liverpool and Manchester.
All three continued at Southport until LNER ownership (1923), when two of the D8s were quickly withdrawn.
The last D8 was withdrawn in 1926.

Technical Details

Cylinders (x2):

(inside)

18x26in.

Motion:

Stephenson

slide-valves

Boiler:

Max. Diameter:

4ft 4in

Pressure:

160psi

Diagram No.:

21

Heating Surface:

Total:

1063 sq.ft.

Firebox:

99 sq.ft.

Tubes:

964 sq.ft. (190x 1.75in)

Grate Area:

18.3 sq.ft.

Wheels:

Leading:

3ft 6.5in

Coupled:

6ft 9.5in

Tender:

4ft 3.5in

Tractive Effort:

14,057lb

(@ 85% boiler pressure)

Wheelbase:

Total:

44ft 5.5in

Engine:

22ft 0in

Tender:

12ft 6in

Weight (full):

Total:

79 tons 7cwt

Engine:

48 tons 4cwt

Tender:

31 tons 3cwt

Max. Axle Load:

15 tons 18cwt

Preservation

The last D8 was withdrawn in 1926, and none survived into preservation.